The present invention relates to exhaust gas purifying device or apparatus and process for an internal combustion engine equipped with an NOx trap catalyst.
Japanese Patent No.2692530 shows a control system for regenerating an NOx absorbing type catalyst by enriching an air fuel mixture temporarily and thereby releasing NOx from the catalyst in a reducing atmosphere. Japanese Patent Provisional Publication No. H7(1995)-332071shows a control system for controlling a direct injection gasoline engine to regenerate an NOx absorbing catalyst.